Sodium ascorbyl phosphate

Sodium ascorbyl phosphate (CAS 66170-10-3) is a phosphorylated, water-soluble derivative of vitamin C, commercially available under trade names including Stay-C 50 and VCP-NA. It is more chemically stable than ascorbic acid itself, resisting oxidative degradation in aqueous formulations where free ascorbic acid would rapidly decompose.

In cosmetic formulations, it functions as both an antioxidant and a skin-conditioning agent. Enzymes in the skin cleave the phosphate group, releasing active ascorbic acid at the site of application, which supports collagen synthesis and neutralises free radicals. This pro-vitamin mechanism allows stable delivery of vitamin C activity in leave-on creams, serums, and suncare products.

Sodium ascorbyl phosphate is supplied as a solid powder and is subject to REACH registration requirements for EU market supply. It is used in personal care and pharmaceutical applications and should meet relevant purity specifications for the intended use. Packaging formats vary by supplier volume requirements.